2 questions: yeast & C18 - (Sep/05/2008 )

HI!

I HAVE TWO (RATHER DIFFERENT) QUESTIONS:

1) I AM NOT USED TO GROWTH YEASTS IN MINIMAL MEDIA. USUALLY WHEN I GROW THEM IN YPD I HARVEST THEM AT A OD OF 0.8-1.0 (HOPE IT'S CORRECT AS I ALWAYS DID LIKE THIS LOL)
MY QUESTION IS AT WHICH OD SHOULD I HARVEST CELLS IF THEY ARE GROWN IN YNB (MINIMAL MEDIUM)?

2) WHY MUST THE pH BE ACIDIC (~2.0) WHEN YOU DESALT PEPTIDES OVER A C18 RESIN?

THANKS TWICE FOR YOUR ANSWERS! LOL

the answer to 2) may be because most silica based stationary phases are not stable at pH above 7.

please don't SHOUT.